Osteoporosis is a major public health threat for over 50% of the population over age 50, with over 10 million Americans estimated to have osteoporosis and another 34 million at increased risk due to low bone mass. Additionally, over 340,000 osteoporotic hip and 700,000 spine fractures are reported annually in patients over age 65. Despite the clinical importance of osteoporosis, it is under-diagnosed and under-treated with only 12- 14% of those who need testing receiving it. To rectify this, O.N. Diagnostics has developed ancillary BCT for clinical use. BCT combines image processing of CT scans, bone biomechanics, and finite element analysis to provide estimates of BMD and whole-bone strength from patient CT scans. The goal of this SBIR project is to develop the ability to provide these BMD and bone strength measures using a wide range of typical clinical CT exams, in which the BCT analysis is performed as an add-on analysis to a CT exam that was ordered for a non-osteoporosis indication, thereby enabling the identification of those patients at high risk o hip and spine fracture while removing the patient inconvenience of undergoing a dedicated osteoporosis scan and maximizing the cost-effectiveness of pre-existing imaging exams. We estimate that up to 8-10 million CT scans taken each year in the U.S. contain the hip or spine and would be technically suitable for ancillary BCT analysis. Our plan is to offer ancillary BCT to those CT patients who meet the current clinical criteria to have a DXA exam but who have not yet had a DXA. In Phase-I of this project, we successfully developed software (VirtuOst) to assess both bone strength and BMD using previously acquired clinical CT scans. This Phase-II project will focus on the remaining technical challenges to the full clinical implementation of ancillary BCT. In Aim 1, we will improve throughput and reliability by automating image processing steps and integrating automatic quality assurance testing into the analysis workflow, eliminating the procedural overhead associated with an analysis and reducing the cost to no more than that of a DXA exam. Utilizing existing image processing steps we will add vertebral facture assessment to add value to BCT. In Aim 2 we will optimize our phantomless calibration technique using patient-specific estimates of x-ray beam energy that will allow repeatable BCT result regardless of CT scanner or acquisition protocol. We will extend BCT analysis to the 50% of abdominal CT exams acquired with intravenous contrast, and address monitoring guidelines for ancillary BCT. Finally, in Aim 4, we will integrate all these advances into a clinical study featuring multiple CT scanners and exam types acquired from a large and demographically diverse patient population. Focusing on clinical translation, we will also perform a cost-effectiveness analysis to determine the most efficient exam types to analyze and which patients would benefit most from ancillary BCT from a health economics perspective. At the end of this SBIR study, we will have expanded the scope and clinical utility of ancillary BCT analysis to at risk patients without DXA exams but with existing CT exams and determined which of these patients BCT will benefit most.